Graduation season is upon us and, with it, platitude-filled speeches. Sometimes students get upset about the speakers; Rutgers students are currently protesting the school’s selection of Condoleezza Rice. But more often, no one is aware of the speakers’ demons until long after the graduation is over. These graduation speakers—and others—would have fared a lot better had they themselves paid attention to the wisdom they provided to students, and the public at large.

“When you know what you are talking about, others will follow you because it’s safe to follow you.” – Richard Fuld

It’s hard to imagine it now, but there was a time when Lehman Brothers CEO Richard Fuld was someone colleges were excited to book as a commencement speaker. In 2006, he returned to his alma mater, University of Colorado at Boulder, to deliver a commencement address—in which he told students about the leadership opportunities that would come with knowing what you were talking about.

Less than two-and-a-half years later, Lehman Brothers became the largest bankruptcy filing in U.S. history.

“I believe happiness . . . comes when you extend yourself and reach out to others. When you reach out with the loving, caring hand of concern to help someone find their way or to give them a little guidance or support along the way.” – Jerry Sandusky

Penn State football’s defensive coordinator Jerry Sandusky promoted himself as a philanthropist and mentor with his Second Mile foundation. To bolster his image, he wrote a self-serving memoir called Touched: The Jerry Sandusky Story. A decade after its publication, Sandusky was indicted and then convicted on 45 counts related to child molestation. He’s currently incarcerated. While his book is out of print, it has become a collectible of sorts: a signed copy recently sold on eBay for $129.99.

“I’ve never been a passive person. I’ve always felt that, if you think something should be changed, it’s your responsibility to actively pursue that change.” — Bob Filner

When California Congressman and later San Diego mayor Bob Filner made those comments, he was reflecting on the volunteer work he’d done as a Freedom Rider, helping to integrate buses when he was a teenager. Unfortunately, as an adult, Filner applied that same can-do spirit to his interactions with women. In 2013, Filner pleaded guilty to felony false imprisonment “by violence, fraud, menace and deceit” and two counts of misdemeanor battery. He had already resigned as mayor because of the allegations, which began with his former communications director alleging that he had demanded kisses and asked that she work without panties, and that he had put her in a headlock.

“It is easier to get into something than to get out of it.” –Donald Rumsfeld

Donald Rumsfeld was fond of circulating his own lists of folksy advice to his subordinates back when he was head of President Ford’s transition team, and later as a White House Chief of Staff. Unfortunately, even the best-laid aphorisms couldn’t save Rumsfeld from a string of legacy-ruining blunders during his service as President George W. Bush’s Secretary of Defense. On February 7, 2003, Rumsfeld spoke to troops and explained that the conflict in Iraq they had just begun would not last long. “It is unknowable how long that conflict will last,” he said. “It could last six days, six weeks. I doubt six months.

“The only barriers in your career are self-imposed.” – Al Dunlap

“Chainsaw Al” Dunlap was, at one time, one of the most respected CEOs in America. His tough, take-no-prisoners approach to cost cutting made him an icon of the 1990s, and his book Mean Business: How I Save Bad Companies and Make Good Companies Great was an instant bestseller. When he was hired as CEO of Sunbeam in 1996, the stock surged close to 50% in a single day. But in 1998, the whole thing collapsed under the weight of management mistakes and aggressive accounting. Dunlap was fired, and the company went into bankruptcy. In 2002, Dunlap settled SEC fraud charges by paying a $500,000 fine and agreed not to serve as an officer or director of a publicly traded company for the rest of his life. Not that anyone was asking him to.

Zac Bissonnette is the author of Debt-Free U and New York Times bestseller How to Be Richer, Smarter, and Better-Looking Than Your Parents. His new book, GOOD ADVICE FROM BAD PEOPLE: Selected Wisdom from Murderers, Stock Swindlers, and Lance Armstrongwas released by Portfolio/Penguin in April. He has written for various media outlets including Glamour, The Wall Street Journal, The Boston Globe, Bloomberg, and The Daily Beast. In August 2013, he was blocked on Twitter by Donald Trump.